Screw shaft element



FIG. 1 is a perspective view of the first embodiment of the screw shaft element showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is an enlarged left side view thereof;

FIG. 5 is an enlarged right side view thereof;

FIG. 6 is an enlarged top view thereof;

FIG. 7 is an enlarged bottom view thereof

FIG. 8 is a perspective view of the second embodiment of the screw shaft element showing of our new design;

FIG. 9 is a front view thereof.

FIG. 10 is a back view thereof.

FIG. 11 is a left side view thereof

FIG. 12 is a right side view thereof

FIG. 13 is an enlarged top view thereof; and,

FIG. 14 is an enlarged bottom view thereof.

The broken lines in the drawings illustrate portions of the screw shaft element and form no part of the claimed design. 

CLAIM The ornamental design for a screw shaft element, as shown and described. 